The present invention generally relates to circuit board apparatus, and more particularly relates to apparatus and methods for mounting a Surface Mount Technology (SMT) device on a circuit board.
As modern circuit boards become more densely packed with electronic components carried thereon, and signal speeds continue to increase, there is a growing need for resistors, capacitors and ferrites that can be surface mount installed, yet be connected to shielded internal traces within the circuit board. Surface Mount Technology (SMT) devices have been previously used in this application and typically have small rectangular block-like configurations defined by an elongated dielectric body portion having electrically conductive end sections.
The conventional technique used in mounting an SMT device on a circuit board and electrically coupling the device between, for example, ground and signal plane portions of the circuit board within its substrate is to (1) form through the substrate a spaced pair of conductively plated through holes, or "vias", that are respectively coupled to the ground and signal planes, (2) form on a side surface of the substrate a spaced pair of electrically conductive mounting pads, each of which is electrically coupled to the plating of one of the through holes, and (3) solder the electrically conductive end sections of the SMT device to the mounting pads on the outer side surface of the circuit board substrate.
The circuit board side surface space requirement inherent in this conventional use of two conductively plated through holes and associated surface mounting pads to connect each SMT device to internal tiers within the circuit board substrate, such as ground and signal planes, becomes considerably less acceptable as the required component density and signal speeds continue to increase in rapidly evolving modern circuit board technology.
From the foregoing it can readily be seen that it would be highly desirable to provide improved apparatus and methods for operatively mounting an SMT device on a circuit board, and electrically coupling the device between interior portions of the circuit board, in a manner requiring less board side surface space than in the conventional SMT device mounting method generally described above. It is accordingly an object of the present invention to provide such improved apparatus and methods.